Pins XTAL1 and XTAL2 are input and output, respectively, of an inverting amplifier which can beconfigured for use as an On-chip Oscillator, as shown in Figure 8-2. Either a quartz crystal or aceramic resonator may be used.This Crystal Oscillator is a low power oscillator, with reduced voltage swing on the XTAL2 out-put. It gives the lowest power consumption, but is not capable of driving other clock inputs, andmay be more susceptible to noise in noisy environments. In these cases, refer to the “Full SwingCrystal Oscillator” on page 32.